Fate of ligno-cellulosic components and urea-nitrogen in urea-ammoniated wheat straw Elangovan A. V.*, Kishan Jai, Sahoo A.1 Department of Animal Nutrition & Feed Technology College of Veterinary Science & Animal Husbandry Mathura - 281 001, India. *Reprint request: Dr. A. V. Elangovan, Division of Nutrition & Feed Technology, Central Avian Research Institute, Izatnagar - 243 122, India. Tel: +91-581-447261; Fax: +91-581-447321; E-mail: elangocari@rediffmail.com
1Present address: Division of Animal Nutrition, Indian Veterinary Research Institute, Izatnagar-243 122, India.
Abstract Effect of both incubation and exposure time on the loss of ammonia-N was tested during the process of urea-ammoniation of wheat straw. The straw chaffed to a size of 5 mm length was ammoniated with 5% urea at 40% moisture level and incubated for 1, 2, 3 and 4 weeks in a air tight glass desiccator having a capacity of 4 kg. Periodically, the incubated lots were exposed, and aired over 3 × 3 sq. ft. area for the determination of N. Representative samples of ammoniated straw were collected after 1,2,3,4,5,6,7,10,14 and 21 days of exposure to determine the DM, CP, CF, ADF, NDF and lignin content in the straw. Due to air drying there was a similar trend in moisture disappearance in all incubated samples with a DM content of 60% on day 1 which air dried to reach a figure of 93% on day 21. The samples from 1 week incubation showed incomplete ammoniation with a CP content of 16.39% on day 1 and it reduced to 10.19% on day 21, a reduction of only 38% due to higher percentage of residual urea-N (51%) compared to 3 and 4 weeks incubated samples. Up on aeration, the CP content on 21st day post exposure was reduced by 38% in 1 and 2 weeks incubated samples compared to 60% in the later. There was a declining trend in CP content which remained almost constant at 6 to 7% in both 3 and 4 weeks incubated lot. No significant difference in CF, ADF and lignin content of treated and untreated straw was seen. However, a reduction of 2to 3 units in NDF and lignocellulose fraction was seen in 3 and 4 weeks incubated samples. From the study of N input to the straw a meagre of 15% N was retained in urea-ammoniated straw resulting in a net gain of only about 55% N by the straw which is available for animal feeding. Top Key words Urea, arnmoniation, straw, ligno-cellulose, nitrogen. Top |